Rotary drums of this type have relatively large dimensions as regards diameter and length and are used in practice for various applications, such as for example in rotary kilns, rotary drum coolers, rotary drum driers and the like. In these known constructions several riding rings are attached to the rotary drum shells and axially spaced from one another, each riding ring being rotatably supported on a supporting roller stand with two supporting rollers arranged symmetrically on both sides of the vertical longitudinal central axis of the rotary drum. The rotary drums of rotary kilns are frequently supported on three or more supporting roller stands distributed over the length of the rotary drum, and the co-operating supporting rollers and riding rings have smooth circumferential surfaces, the riding rings being attached to the outer circumference of the rotary drum loosely and with lubrication and with bearing plates interposed (this lubrication is necessary in order to prevent material breaks on the bearing plates). The rotary drive of these known rotary drums is generally provided by gear rings attached to the rotary drum shell and by means of driving pinions which are connected to a reduction gear and at least one drive motor. The drive arrangements thus formed not only necessitate technically demanding components, such as for example gear rings, driving pinions and the like, but also involve correspondingly high expenditure on lubrication and maintenance.
The object of the invention, therefore, is to provide a rotary drum of the type referred to which is distinguished by an economical yet reliable support as well as a simple, economical and efficient rotary drive.